Switchable roller finger followers with varying lift modes are known. Typically, such finger followers have an outer lever with one end that contacts a valve stem. An inner lever is located within a cavity of the outer lever and houses a cam follower that contacts a cam to provide motion to the finger follower to open or close a valve. One end of the outer lever or the inner lever is supported on a hydraulic lash adjuster. A coupling device is used to lock the inner lever in a fixed position relative to the outer lever. When the inner lever is locked to the outer lever via the coupling device, the movement translated by the cam to the finger follower is translated into movement of the valve via the valve stem. In order to switch the finger follower to a different lift mode or to deactivate the finger follower, the coupling device is released and the inner lever is unlocked and can travel freely up and down in conjunction with the cam without transferring the cam motion to the outer lever and valve stem.
One known type of coupling device includes a coupling pin that moves longitudinally between the inner lever and the outer lever to switch between a locked mode and an unlocked mode. The coupling pin is positioned within one of the inner lever or the outer lever, and the coupling pin has a coupling flat that engages with a coupling projection formed on the other one of the inner lever or the outer lever. It is critical to prevent rotation of the coupling pin so that the coupling flat remains rotationally aligned with the coupling projection to allow for reliable engagement when the coupling device is engaged. One known type of anti-rotation feature is shown in FIG. 1, which illustrates a switchable roller finger follower 1 according to the prior art having an outer lever 2 and an inner lever 4. A transversely mounted pin or needle 3 extends over a coupling flat 7 of the coupling pin 5. The transversely mounted needle 3 performs the sole function of preventing rotation of the coupling pin 5. Also shown is a separate clip 9 that provides for retention of the finger follower 1 on an associated hydraulic lash adjuster assembly.
A more cost-effective solution would be desirable that provides an anti-rotation feature for the coupling pin as well as the retention feature.